Hey Guys, Just a quick update.
I contacted the guys at Medalion. The MDC-1600 is "Not repairable" so I was a little annoyed but they were realy helpfull and sorted me out with a new unit for $270 delivered to Melbourne Australia in 4 days... AWESOME!!!
I pulled the medalion MDC from the boat and managed to seperate it using a heat gun to soften the glue and lever it open, but it still cracked. Looks like the water has done some dammage. Was going to try to repair and keep as a spare but.... Considdering it took 12 years before this one broke, it might be a fruitless exercise?